Machine for grinding disk knives



June 20, 1933. F. 0. BENNETT MACHIN E FOR GRINDING DISK KNIVES Filed May 22, 1950 3 Sheets-Sheet 1 IMM- WI mm INVENTOR ATTORNEYS,

June 20, 1933. F. o. BENNETT MACHINE FOR GRINDING DISK KNIVES Filed May 22, 1950 3 Sheets-Sheet 2 BY W 7% ATTORNEY June 20, 1933. O BENNETT 1,914,879

MACHINE FOR GRINDING DISK KNIVES Filed May 22, 1930 5 Sheets-Sheet 5 HH lli ATTORNEYS Patented June 20, 1933 UNITED STATES PATENT Fries FREDERICK O. BENNETT, OF NEW YORK MILLS, NEW YORK, ASSIGNOB, TO NEW YORK MILLS CORPORATION, OF NEW YORK MILLS, NEW YORK, A CORPORATION OF NEW YORK MACHINE FOR GRINDING DISK KNIVES Application filed May 22,

My invention relates to improvements in machines for grinding circular knives and the object of my invention is to produce a U simple, easily operated machine which will F5, enable knives of the kind referred to to be quickly and accurately ground.

My invention is especially intended to provide a structure in which the circular knives will be ground with great accuracy so that 10, the cutting edge will be nicely centered. In some operations, it is very essential that this centering of the edge be nicely carried out. For example, in cutting the pile of pile fabric. In such operations, a great number of knives 15 are mounted on a common shaft and they cut the looped threads which produce the pile. It follows that if theknives are not accurate, the piles will be unevenly cut and the fabric injured. in My invention, however, is not limited to grinding knives of this character but it is applicable to grinding nicely any circular knives. In carrying out my invention, I use a rotary work holder or chuck on which a knife can be easily and accurately placed, and arrange abrasive wheels in different planes which are simultaneously and similarly movable in and out with relation to the'knife to be ground so that they act at the same time on opposite bevels of the rotating disk and similarly and accurately grind each bevel. This arrangement makes it easy to produce so-called hollow edges, and in connection with the foregoing, I employ various details which conduce to quick and accurate work.

Reference is to be had to the accompanying drawings forming a part of this specification, in which similar reference characters indicate correspondingparts in all the views.

Figure 1 is a sectional plan of the grinding machine.

Figure 2 is a front elevation thereof. Figure 3 is a broken side elevation of the machine.

Figure 4 is a detail of a blank disk or knife disk.

Figure 5 is a view of the disk after it has been ground; and

Figure 6 is a diagrammatic detail show- 1930. Serial No. 454,691

ing how the abrasive wheels simultaneously act on opposite sides or bevelsof the knife disk.

In Figures 4 and 5 I have shown the unground and ground knife disks or blanks 10. The blank usually has a bore 11 so that it can be placed on a shaft and the edges are beveled as shown at 12 to produce the edge portions. It is customary also to leave a projecting part 13 on the inner edge of the blank to engage a corresponding notch on the shaft which carries it and 011 the work holder or chuck on which it is ground so that the blank will not turn with respect to the shaft, but will turn firmly with the shaft or the work holder or chuck.

In grinding the blank 10, it is placed upon the core of a table 14 which preferably turns on a vertical axis and affords a broad, firm support for the knife blank while the part 15 tapers, that is, it is like a truncated cone, so that when the disk is placed on it, it will be accurately centered. The member 15 is notched as at 16 to receive the part 13 of the knife disk and so hold it from turning with respect to its holding. A presser foot 17 fits nicely over the member '15 so as to clamp firmly upon the knife disk and bind it between itself and the table 14, while the presser foot is held in place by a nut 18 engaging the driving shaft 20, as shown by dotted lines at 19. Thus, the parts 14:, 15 and 17 form a work holder or chuck which rotates the disk it carries, forms a stable support for the disk which prevents the disk from being warped or bent in the grinding operation and thus injured.

The work holder which I have above described may be rotated in any convenient way, but I have shown the shaft 20 held vertically in a bed 21 and driven by a gear connection 22 with a motor 43, but obviously the means for rotating the work carrying chuck is not important. The bed 21 forms the bottom of the frame or housing 2e and mount- 95 ed in this are abrasive wheels 25, 25 which are, respectively, a little above and a little below the plane of the disk 10 to be ground, so that when the rotating grinding wheels, above referred to, are moved into contact 100 bearings 27, 27 and the bearings are supported in vertically adjustable brackets 28, 28', see Figure 2, so that the wheels 25, carried thereby can be very nicely adjusted tothe exact plane required. The brackets to this end are pivoted as at 29 to a post 30 or other part attached to the movable carriages 31, 31 which are adjustable in and out with relation to the table 14 and are guided on the tracks 32 in a manner common to sliding carriages.

The vertical adjustment of the brackets 28, 28 is'efiected by the adjusting screws 33 which are j ournaled in the brackets as shown and engage threaded parts of the carriages 31. Suitable stops or bumpers 34 are arranged in the paths of the carriages 31 and at the outer parts of the apparatus to limit the outward movement of thecarriages.

The carriages and the grinding wheels which they carry are simultaneously but oppositely moved by an operating lever 35 which is arranged as shown best in Figure 1. This lever is journaled on the shaft 20, as shown in the drawings, and at its outer end it has a sliding connection 37 vwith a turn buckle 38 connecting with a boss or lug 39 on the carriage 31, while nearthe inner end of the lever and at the same distance from its central pivot is a sliding connection 37 but with a turn buckle 38' connecting with a lug 39 on the carriage 31. Thus, it will be seen that by moving the lever on its pivot. the carriages and the abrasive wheels carried thereby will be similarly but oppositely moved. In practice, the movement is small, but in the drawings, the wheels are shown as having a larger spread so that the construction and operation may be made clearer.

The shafts 26, 26' must obviously be driven at thesame speed in order that each grinding wheel shall produce the same grinding effort as the other. I have shown suitable means for driving which, however, can obviously be changed at will without affecting the invention. 7

As illustrated, the shaft 26 has a pulley 40 connected bya belt 41 with a pulley 42 on the jack shaft 4:4,while the shaft 26 has a pulley 40 connected by a belt 41 with a pulley 43 on the shaft 44. The shaft 44 is shown as being driven by the pulley 45 and belt 46 65 connecting with a pulley 47 on the shaft 48 ried by shafts 26, 26, each mounted in stable of a motor 49 which is shown supported on a bracket 50.

The driving mechanism of the rotating parts is not important, and it will be under- Y stood that the shafts 20, 26 and 26 can be driven in any other practical way without affecting the invention.

From the description it will be seen that a disk canbe quickly and securely clamped and centered in its work holder, that is on the parts 15, 1 1, that it will'be held firmly so that it will not buckle or twist while being ground, and that by moving the lever 35, the rapidly moving abrasive wheels 25, 25 can be brought quickly and accurately into engagement with the disk so as to nicely grind it. It will also be seen that the grinding wheels can be easily adjusted as to their plane of movement and that by reason of the connection between the carriages 31 and the op erating lever 35, the amount of movement of the carriages can be readily adjusted.

It will be clearly understood from the foregoing description that the important things are to have the work holding disk or chuck arranged so as to rotate in a plane be tween those in which the grinding wheels travel and to have these rotating grinding wheels move back and forth with relation to the disks on which the work is to be performed and, further, that the details of the structure otherwise can be considerably changed without affecting the principle of the invention.

,I claim:

1. In a structure of the kind described, comprising a rotatable disk holding chuck, carriages movable back and forth on opposite sides of the chuck axis, a lever adjustably 5 connected to the carriages to simultaneously 4 but oppositely move them, and rotatable grinding wheels mounted on the carriages and. disposed in planes on opposite sides of a disk in the chuck.

2. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of said chuck; a support on each of said carriages; and a rotatable abrasive wheel mounted on each of said supports and adapted to engage a disk held by said chuck at diametrically spaced points on said disk.

3. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of said chuck; asupport pivoted on each of said carriages; a rotatable abrasive wheel mounted on each of said supports and adapted to engage a disk held by said chuck at diametrically spaced points on said disk; and means for pivotally adjusting said supports on said carriages to move said cutters toward or away from opposite sides of said disk.

4. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of said chuck; a support pivoted on each of said carriages; a rotatable abrasive wheel mounted on each of said supports and adapted to engage a disk held by said chuck at diametrically spaced points on said disk; means for pivotally adjusting said supports on said carriages to move said cutters toward or away from opposite sides of said disk; and means for simultaneously moving said carriages in opposite directions to cause said wheels to engage said disk.

5. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of the axis of said chuck; supports on each of said carriages; rotatable abrasive wheels mounted on each of said supports and adapted to engage diametrically spaced portions of a disk held by said chuck at opposite sides of said disk.

6. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of the axis of said chuck; supports pivoted on each of said carriages; rotatable abrasive wheels mounted on each of said supports and adapted to engage diametrically spaced portions of a disk held by said chuck; and means for pivotally adjusting said supports on said carriage to move said cutters toward or away from opposite sides of said disk.

7. A grinding machine comprising a rotatable chuck for holding a cutter disk; a pair of movable carriages at opposite sides of the axis of said chuck; supports pivoted on each of said carriages; rotatable abrasive wheels mounted on each of said supports and adapted to engage diametrically spaced portions of a disk held by said chuck; means for pivotally adjusting said supports on said carriages to move said cutters toward or away from opposite sides of said disk; and means for simultaneously moving said carriages in opposite directions to cause said wheels to engage diametrically spaced portions of said disk.

8. A grinding machine comprising a rotatable chuck for holding a cutter disk; rotatable grinding wheels movable toward and away from said chuck in a single plane normal to the plane of a disk held by said chuck; and means for moving said wheels in opposite directions in said plane into engagement with diametrically spaced portions of said disk.

9. In a grinding machine; a rotatable work holding chuck comprising a support, a tapering element for centering a disk on said support, and a presser foot closing over said member to clamp a disk between itself and said support; and rotatable grinding wheels movable back and forth with relation to the chuck and in planes at opposite sides of the axis of said chuck.

10. In a grinding machine; a rotatable work holding chuck comprising a support, a tapering element for centering a disk on said support, and a presser foot closing over said member to clasp a disk between itself and said support; rotatable grinding wheels movable back and forth with relation to the chuck and in planes at opposite sides of the axis of said chuck; and means for adjusting said grinding wheels in said planes to move said wheels toward or away from opposite faces of a disk held by said chuck.

In testimony whereof, I have signed my name to this specification this 17th day of May, 1930.

FREDERICK O. BENNETT. 

